Pushbutton switch detent



Feb. 20, 1968 c. A. BARNEY PUSHBUTTON SWI TCH DETENT Filed March 15, 1967 LK/ //i' IFIG. 3

United States Patent ()fiice 3,370,143 Patented Feb. 20, 1968 3,370,143 PUSHBUTTON SWITCH DETENT Charles Azel Barney, Stow, Mass, assignor to Ark-Les Switch Corporation, Watertown, Mass, a corporation of Massachusetts Filed Mar. 15, 1967, Ser. No. 623,337 7 Claims. (Cl. 200--166) ABSTRACT OF THE DISCLOSURE A pushbutton switch including a push rod mounted for reciprocating movement in a direction perpendicular to a wall of the switch. The push rod includes a projecting portion of increased width and extends through an opening in the wall and a corresponding opening in a resilient insulating sheet mounted in the wall. The width of the wall opening is greater than that of the projecting portion of the push rod; the width of the corresponding sheet opening is less than that of the projecting portion. The sheet portions defining the opening are resiliently deformable.

This invention relates to pushbutton switches.

It is a primary object of the present invention to provide a simple, inexpensive and reliable detent structure for positioning the reciprocating actuating members of pushbutton switches.

The invention accomplishes its objects by providing a pushbutton switch including a push rod mounted for reciprocating movement in a direction perpendicular to a wall of the switch. The push rod, which includes a projecting portion of increased width, extends through an opening in the wall and a corresponding opening in a resilient insulating sheet mounted on the wall. The width of the wall opening is greater than the width of the projecting portion of the push rod; the width of the sheet opening is less than that of the projecting portion and the portions of the sheet defining the opening are resiliently deformable for permitting the push rod to reciprocate and to retain the push rod in its inner position.

Other objects, features and advantages will appear from the following detailed description of a preferred embodiment of the invention, taken in conjunction with the attached drawings, in which:

FIG. 1 is a plan sectional view of portions of a switch constructed according to the present invention;

FIG. 2 is a perspective view of elements of the switch of FIG. 1; and

FIG. 3 is a plan view of a detent component of the switch of FIG. 1.

Referring more particularly to the drawings, there is shown a pushbutton switch including a generally rectangular housing 12 having a top wall 14, and a plurality of push rods 16 extending through rectangular slots 18 in top wall 14 for reciprocating movement in a direction generally perpendicular to wall 14. An actuating pushbutton 20 is mounted on the outer end of each push rod 16. As thus far described, the construction of switch 10, together with the means (not illustrated) in which the push rods cooperate with other switch operating mechanisms to provide the desired switching, are well known in the art.

The present invention, as previously mentioned, is concerned with a novel detent structure for holding push rods 16 in their actuating, depressed positions. Each push rod 16 is of generally rectangular cross-section and includes a projecting lug 22 extending outwardly from one side of the push rod. Each slot 18 in top wall 14 of housing 12 is of sufiicient width to allow lug 22 to pass therethrough when the push rod 16 is reciprocated.

An insulating, flexible, organic plastic detent sheet 24 is mounted on the inner face of wall 14. Detent sheet 24 includes a group of three rectangular slots associated with each push rod 16, a center slot 26 through which the push rod passes and relief slots 28, one on each side of center slot 26. The width of slot 26 is greater than the width of the major portion of push rod 16, but less than the width of the portion including lug 22. The total width of each pair of relief slots 28 is slightly greater than the additional width of push rod 16 attributable to lug 22.

When push rod 16 is moved from its outer position in which lug 22 is above sheet 24 (pushbutton 20a in FIG. 1) to its inner position in which they are below sheet 24 (pushbutton 20c), lug 22 engages the resilient portions 30 of sheet 24 between slots 26 and 28 and forces them outwardly and away from each other (pushbutton 20b) to permit the lug to pass through slot 26. When the push rod has reached its inner position, it is retained there by sheet portions 30 which, being resilient, have returned to their original positions.

Other embodiments within the scope of the following claims will occur to those skilled in the art.

What is claimed is:

1. A pushbutton switch comprising:

a housing having a wall with an opening extending through the thickness thereof;

a thin, substantially planar resilient insulating sheet having an opening extending through the thickness thereof mounted on said wall with said opening of said sheet aligned with said opening of said wall; and,

at least one push rod mounted on said housing and extending through said openings for reciprocating movement in a direction generally perpendicular to said wall between inner and outer positions;

said push rod including a projecting portion of increased width intermediate the length thereof;

said opening in said wall having a width greater than the width of said projecting portion and said opening in said sheet having a width less than the width of said projecting portion;

the portion of said sheet defining said opening therein being resiliently deformable for permitting passage of said projecting portion therethrough during movement of said push rod between said inner and outer positions and engaging said projecting portion for retaining said push rod in said inner position.

2. The switch of claim 1 including a plurality of push rods mounted on said housing for reciprocating movement between inner and outer positions;

each of said push rods including a projecting portion and extending through an opening in said wall and a corresponding opening in said sheet;

each said opening in said wall having a width greater than the width of the projecting portion of the push rod extending therethrough and each said opening in said sheet having a width less than said width of the projecting portion, the portions of said sheet defining said openings being resiliently deformable.

3. The switch of claim 1 in which said portions of said sheet adjacent each of said corresponding openings are relieved through the thickness of said sheet for permitting passage of said projecting portions through said corresponding openings.

4. The switch of claim 1 in which said push rod is of generally rectangular cross-section, said corresponding opening comprises a rectangular slot, and including a pair of rectangular relief slots extending through the thickness of said sheet located adjacent and parallel with said corresponding opening, one of said relief slots being located on each side of said corresponding opening.

5. A detent structure for a pushbutton switch comprising a thin substantially planar organic plastic resilient sheet including a plurality of groups of parallel rectangular slots extending through the thickness of said sheet;

each said group having a central slot and at least one relief slot located on a longitudinal side of said central slot; the portions of said sheet between said central slot and said relief slot being resiliently deformable for permitting an object having a width greater than the width of said central slot to pass therethrough. 6. The detent structure of claim 5 in which each said 4 1 group includes a central slot and a relief slot located on each longitudinal side of said central slot.

7. The detent structure of claim 6 in which said slots are longitudinally coextensive.

References Cited UNITED STATES PATENTS 3,l83,3 l5 5/1965 Kiely 200-5 ROBERT K. SCHAEFER, Primary Examiner.

H. O. JONES, Assistant Examiner. 

